Abstract

Automatic vehicle location (AVL) systems are increasingly being introduced across bus networks worldwide to the benefit of passengers and operators. The performance of these systems depends on the quality of the input data, and the accuracy of bus stop locations is among the most important data. Global Positioning System (GPS) devices are used to collect measurements when a bus opens its doors for the purpose of validating bus stop locations. London Buses intends to apply such an approach to validate the locations of all its 19,000 bus stops in London. Three approaches are tried: two based on univariate density estimation and one based on multivariate density estimation. In all cases, a kernel estimator is used. Data collected by the new iBus AVL system along a London bus route are used to determine the best approach. Results suggest that a univariate kernel density estimate with a correction factor to allow for the stop being at the side of the road performs best.